Influence of Endosperm Starch Composition on Maize Response to Fusarium temperatum Scaufl. & Munaut

Abstract

Fusarium temperatum Scaufl. & Munaut is a newly described taxon belonging to the Fusarium fujikuroi species complex (FFSC) and a frequent causative factor of maize ear rot. The aim of the present study was to determine the responses to the disease in maize populations differing in endosperm features that were classified to flint, dent, and a group of plants with intermediate kernel characteristics. In inoculation studies, substantial variation of host response to the fungus was found among the tested maize types. The dent-type kernels contained significantly less amylose (28.27%) and exhibited significantly higher rates of infection (IFER = 2.10) and contamination by beauvericin (7.40 mg kg−1) than plants of the flint maize subpopulation. The study documents a significant positive correlation between the Fusarium ear rot intensity (IFER) and ergosterol content (the R value ranged from 0.396 in 2015 to 0.735 in 2018) and between IFER and the presence of beauvericin (the R value ranged from 0.364 in 2015 to 0.785 in 2017). The negative correlation between (IFER) and amylose content (ranging from R = −0.303 to R= −0.180) stresses the role of the endosperm starch composition in the kernel resistance to Fusarium ear rot. The conducted study indicated that the risk of kernel infection and contamination with fungal metabolites (beauvericin and ergosterol) was associated with the maize type kernels.

Fungi complicit in oak powdery mildew infection in the Oława Forest District

“…A major threat to oak trees in both natural and artificial restoration is the fungi of the genus Fusarium, which was one of the most frequently isolated. In artificial restoration, another abundant type is Alternaria (Król et al, 2015), and the same relationship is confirmed by the study of Wit et al (2015). In natural regeneration, the next most abundant type was Trichoderma.…”

“…e research in the Oława Forest District confirms the presence of the above Fusarium species on oaks, however, apart from these three, F. sporotrichioides, F. dimerum, F. graminearum, and four species: F. equiseti, F. graminum, F. poae, F. sambucinum in smaller quantities were the most numerous. Fungi of the type Fusarium were isolated, also from diseased oak shoots, in the study of Wit et al (2015), confirming the presence of these pathogens on this tree species. Fungi of the genus F. oxysporum can also be found on other tree species.…”

“…In recent years, oak dieback has been an increasing problem in forests, mainly of new 1-3-year-old regenerations, as well as of young specimens up to 25 years old (Wit et al, 2015). Oak dieback is a large and still not fully diagnosed problem both in Poland and worldwide (Oszako et al, 2009(Oszako et al, , 2013.…”

“…On the one hand, climate change and the ensuing unfavorable abiotic factors such as long periods of drought with high tem-peratures or sulfurous frosts are responsible for this, as well as falling groundwater levels, making it harder for trees to draw water from increasingly deep aquifers (Andrzejczyk, 2009;Corcobado et al, 2014;Oszako et al, 2013). On the other hand, biotic stressors, primarily pathogens such as fungi, are responsible for weakening and ultimately dying (Wit et al, 2015).…”

Genetic variation in ZmWAX2 confers maize resistance to Fusarium verticillioides

“…In contrast, ZmWAX2 ‐mediated resistance carries no differences in important agronomical traits under normal growth conditions (Figure S7 ) and even remarkedly increases the corn yield upon F. verticillioides stalk rot (Figures 5 and 6 ). Interestingly, we observed that the morphology and arrangement of endosperm starch granules and invasive hyphae of internal F. verticillioides are quite different between the zmwax2 mutant and ZmWAX2 overexpressor seeds (Figure S9 ), which is consistent with a recent report that endosperm starch composition is associated with maize resistance to fungus infection (Wit et al ., 2022 ). Given that ZmWAX2 is a homologue of genes involved in cuticular wax biosynthesis according to phylogenetic analysis (Figure S2 ), we hypothesize that ZmWAX2 confers a durable and broad‐spectrum resistance to multiple fungal pathogens, at least F. verticillioides in maize.…”